Effects of Lemborexant on Motor-sleep Comorbidity in Parkinson's Disease

Prior treatment

• 7\. Use of any orexin receptor related medication within the past 3 months.
• 8\. Previous history of cataplexy or known reduced orexin levels;
• 10\. Use of other sleep-promoting medications within the past 3 months.

Other illness

• 1\. History of or diagnosis with a severe psychiatric disorder, such as depression, anxiety disorders, schizophrenia spectrum disorders, or bipolar disorder;
• 2\. Presence of a clinically defined neurological disorder (assessed via self-report), including but not limited to: any condition potentially associated with increased intracranial pressure, space-occupying brain lesions, history of stroke, transient ischemic attack within the past 2 years, cerebral aneurysm, dementia, or multiple sclerosis;
• 3\. Severe cognitive impairment (Mini-Mental State Examination (MMSE) score below 24) or inability to complete questionnaires independently;
• 4\. Chronic obstructive pulmonary disease (COPD) or any lifelong history of sleep-related breathing disorders, such as sleep apnea;

Other

• 5\. Excessive daytime sleepiness, defined as self-reported daily daytime napping ≥ 1 hour per day on ≥ 3 days per week;
• 6\. Regular caffeine consumption;
• 9\. Inability to read or understand Chinese;

• 1\. Aged 50 years or older;
• 2\. Diagnosed with idiopathic Parkinson's disease according to the Movement Disorder Society Clinical Diagnostic Criteria for Parkinson's Disease (2015), with a Hoehn \& Yahr stage of 1 to 4;
• 3\. Disease duration of ≥ 2 years since diagnosis, clinically stable, and able to comply with the research assessments and interventions;
• 4\. Diagnosis of insomnia disorder meeting the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), with an Insomnia Severity Index (ISI) score of ≥ 15;
• 5\. Stable medication regimen for at least 4 weeks prior to the study;
• 6\. Signed informed consent form, with the participant or their legal guardian able to understand and willing to participate in this study.